Follistatin 344
Muscle In trials Human trials
Also called FST-344, Activin-binding protein
A lab-made form of follistatin, a natural protein that binds and neutralizes myostatin and activin. Because those signals limit muscle growth, raising follistatin increased muscle mass in animal studies. It was also the basis of gene-therapy trials in muscular dystrophy.
Why people take it
What studies report
- Large gains in muscle mass in mice and monkeys
- Increased thigh muscle and walking distance in a small gene-therapy trial in Becker muscular dystrophy
In practice Unapproved use
- A high-cost, short-run choice in competitive bodybuilding
Reported real-world use, not evidence and not a recommendation.
Worth knowing: Human data used gene therapy, not the peptide itself. Blocking myostatin broadly also affects reproductive hormones.
Status: Animal research; small gene-therapy trials in humans. Not approved.
- Route
- Subcutaneous injection, from reconstituted lyophilised powder
- Molecular weight
- ≈38 kDa
- Available as
- 1 mg
Educational information only. Nothing here is medical advice, a dosing protocol, or a recommendation to use any compound. Most entries describe substances not approved for human use. Talk to a licensed clinician before acting on anything you read here. How to read these entries.